The Birth That's Right for You by a doctor and a midwife, helps explain the birth process without inundating the reader with horror stories and heavy opinions. Their premise is that what comes naturally to you defines how you will birth your baby. (IE, if you don't breathe through your teeth, it's not going to come in that handy when you're fightin' through those contractions.)
I like to be informed without being influenced, so this book helped me feel more confident about going into labor and delivery. A little more information about what the drugs actually do -- and their negative/positive affects would have been helpful.